The Lange Groenendaal street in Gouda, NL

Gouda is, of course, better known for the cheese of the same name. From a crypto enthusiast’s point o view however, the Lange Groenendaal street is more interesting. This picture was taken at 52.01019830856444, 4.706937318704833.

The Lange Groenendaal street is located in the downtown area of Gouda.

Source: AI-generated

The letter-shaped paving stones begin at the southwest end of the street.

Among other things, the letters M, O, H, and L can be seen here.

The sequence of letters has no apparent meaning.

I discovered this street purely by chance. Like many cryptological landmarks, it isn’t particularly well known. Of course, I’ve included the street in my Cryptologic Travel Guide.

At first, I couldn’t make head or tail of the sequence of letters.

But I didn’t believe it was a random sequence either.

There are 95 letters.

There is no information sign or anything similar on the street.

There’s a Lutheran church on that street. Does it have anything to do with this?

It is not clear in which direction the letters should be read.

When I was there, it seemed like no one else but me was interested in the stones.

In downtown Gouda, you’ll find many references to the cheese of the same name. Does this sequence of letters have anything to do with it, too?

Question after question

This is where the letter-shaped paving stones end. But the street continues on.

I finally found the answer online: Each letter is the first letter of one of Luther’s 95 theses. In Dutch, the work is titled “95 stellingen van Maarten Luther.” Hein Driest, an urban planner for the municipality of Gouda from 2000-2013, is credited as the creator. The stones were thus deliberately designed as a modern allusion to the neighboring Lutheran church.

From a cryptographic standpoint, this inscription is therefore an abbreviation cipher.